"21. Because both Section 138 and 139 require that
the Court "shall presume" the liability of the drawer
of the cheques for the amounts for which the cheques
are drawn, as noted in State of Madras vs A.
Vaidyanatha Iyer, AIR 1958 SC 61, it is obligatory on
the Court to raise this presumption in every case
where the factual basis for the raising of the
presumption had been established. "It introduced an
exception to the general rule as to the burden of proof
in criminal cases and shifts the onus onto the
accused" (ibid). Such a presumption is a presumption
of law, as distinguished from a presumption of fact
which describes provisions by which the Court "may
presume" a certain state of affairs.